Doctors may put a thumb spica cast on an individual's thumb if it is broken, according to the American Academy of Orthopaedic Surgeons. In some cases, doctors may use a lightweight splint for the broken thumb. For more severe cases, surgery may be needed.
The thumb spica cast extends from the forearm to the hand and onto the thumb, immobilizing the thumb joint. This cast is worn for three to six weeks, varying depending upon the patient's age, according to the American Academy of Orthopaedic Surgeons.
If surgery is performed, a cast remains on the thumb for two to six weeks, according to the Virtual Sports Injury Clinic. Surgery is needed if there is much movement amid the fracture or there are multiple fractures.